1. Field of the Invention
The present invention relates to a paper delivery device provided in an image forming apparatus for forming an image on a paper and delivers the paper on which the image is formed to the outside.
2. Description of the Related Art
Conventionally, there has been known an image forming apparatus which delivers papers on which images are formed to a paper exit tray while sorting the papers in accordance with the number of copies. For example, there has been known an image forming apparatus equipped with a shift frame which is slidable back and forth in a roller axis direction of a paper delivery roller.
In this image forming apparatus, the shift frame is moved in the direction perpendicular or substantially perpendicular to a paper feeding direction of papers and, thereafter, papers on which images are formed are delivered to a paper exit tray (shift sort).
Further, in the image forming apparatus which forms images on papers by electrophotography, at the time of heating a paper for fusing toner to the paper, moisture is evaporated from a heated surface of the paper. It has been known that, as a result of the evaporation of moisture, the heated surface of the paper is contracted so that the paper curls.
To prevent such curl, there has been known a paper delivery device equipped with a decurling mechanism which eliminates curl generated on a paper by a plurality of driven rollers which are brought into contact with a curved surface of a drive roller at the time of delivering the paper.
Conventionally, in mounting the shift sorting mechanism and the decurling mechanism described above on the image forming apparatus, these mechanisms are mounted separately from each other. As a result, it has been impossible to downsize the image forming apparatus having functions of both mechanisms.